Gruen Airflight 2 in 1 C.1960s

Double Tap 6 to Unlock Tap Functions / Single Tap to Lock tap functions.

Centre to Zoom. Multi

3 to toggle Date window - On / Off.

9 to toggle Dim - Auto / On / Off.

Between 10 and 11 to change faces.

12 to rotate Bezel.

Second Hand Battery Reserve in Dim.